The executive director of California's health insurance exchange said Monday that he is hiring 400 call-center workers, many in Fresno, with the goal of alleviating telephone backlogs that have frustrated those applying for health care.

Peter Lee, executive director of Covered California, formally announced the staffing increase in a visit to a Fresno call center, where 250 new employees began training on their first day of work. He expects the extra help to bring down the average wait time of 51 minutes and better serve speakers of Spanish and other languages. In the coming weeks, Lee said the exchange will hire another 150 people and start training them.

This staffing boost - increasing workers by about 50 percent - comes in answer to barriers causing frustration and potentially preventing people from enrolling. Californians need to continue signing up to make the state's health exchange viable.

Lee acknowledged that there have been problems.

"We've heard their complaints. We've heard their concerns," Lee said. "We've stepped up to say we're going to make it right."

Covered California is the state's health insurance exchange under the federal Affordable Care Act. Since it was launched last fall, 625,000 Californians have signed up. Open enrollment ends March 31, which Lee expects to be a busy month as residents are reminded that if they fail to get covered, they will be fined.

The increased customer service from Covered California also means more call-center workers in Rancho Cordova and Contra Costa County. The exchange will add phone lines, make the website easier to use and create an option to get help through online chat. An automated phone system will answer commonly asked questions callers have without requiring them to wait, Lee said.

Lee couldn't immediately say how much the new employees will cost, but he said their salaries will come from $155 million in extra funding the federal government gave California. After the grant money is gone, Covered California by law is supposed to run on a premium added to customer costs, which Lee said currently equal 4 percent.

Lee said his aides weeks ago recognized that they needed more help for uninsured residents trying to enroll, and they started planning for the fixes that became apparent Monday.

"The fact people are starting (work) today doesn't mean we started today," he said.